Automatic sheet feeder and scan apparatus with assemblies for transporting sheet at different speeds

ABSTRACT

An automatic sheet feeder includes a sheet passageway, an opening formed in the sheet passageway and a sheet transporting mechanism. The sheet transporting mechanism transports a sheet through the sheet passageway. The sheet transporting mechanism includes a first transporting assembly and a second transporting assembly, which is disposed downstream of the first transporting assembly. The first transporting assembly transports the sheet to the opening at a first speed, and the second transporting assembly transports the sheet away from the opening at a second speed higher than the first speed. A scan apparatus using the automatic sheet feeder is also disclosed.

This application claims priority of No. 097119459 filed in Taiwan R.O.C.on May 27, 2008 under 35 USC 119, the entire content of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an automatic sheet feeder and a scan apparatus,and more particularly to an automatic sheet feeder with assemblies fortransporting a sheet at different speeds, and a scan apparatus using theautomatic sheet feeder.

2. Related Art

A conventional automatic sheet feeder usually has a sheet detector or aplurality of sheet detectors for detecting a trailing edge and a leadingedge of a sheet. Then, the sheet-fed roller in the feeder is controlledand timely stopped according to the signal outputted from the sheetdetector, such that a delay in the time for initiating the feeding of anext sheet is effected and a sequence of sheets are separated by gapsbetween them. The sheets are scanned intermittently by a scan module,and discrete images of the sheets are thus generated.

However, the automatic sheet feeder comprising the sheet detector has acomplicated control circuit, while the hardware cost thereof isincreased. Moreover, the automatic sheet feeder for combining with aflatbed scanner usually is the U-type automatic sheet feeder, whichneeds more rollers and components, and of which the manufacturing costand the price are relatively high.

Thus, it is an important subject of the invention to provide anautomatic sheet feeder with fewer components and of a lower cost.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an automatic sheetfeeder with fewer components and of a lower cost, which has atransporting mechanism for transporting a sheet at different speeds. Thedifference in speed will generate references for a subsequent imageprocessing procedure, that is, page separation, by which a discreteimage of the sheet can be obtained without the sheet detector andrelated circuits.

To achieve the above-identified object, the invention provides anautomatic sheet feeder comprising a sheet passageway, an opening formedin the sheet passageway and a sheet transporting mechanism. The sheettransporting mechanism transports a sheet through the sheet passageway.The sheet transporting mechanism comprises a first transporting assemblyand a second transporting assembly, which is disposed downstream of thefirst transporting assembly. The first transporting assembly transportsthe sheet to the opening at a first speed, and the second transportingassembly transports the sheet away from the opening at a second speedhigher than the first speed.

The invention also provides a scan apparatus including an automaticsheet feeder and a scan module. The automatic sheet feeder comprises asheet passageway, an image-processing area and a sheet transportingmechanism. The sheet transporting mechanism sequentially transports afirst sheet and a second sheet through the sheet passageway. The sheettransporting mechanism comprises a first transporting assembly and asecond transporting assembly disposed downstream of the firsttransporting assembly. The first transporting assembly transports thefirst sheet and the second sheet to the image-processing area at a firstspeed, and the second transporting assembly transports the first sheetand the second sheet away from the image-processing area at a secondspeed higher than the first speed. The scan module continuously scansthe first sheet and the second sheet within the image-processing areaand generates a continuous image. The continuous image comprises a firstsheet image corresponding to the first sheet, a second sheet imagecorresponding to the second sheet and a gap image corresponding to a gapbetween the first sheet and the second sheet.

The invention can continuously scan multiple sheets without using asheet detector and generate gaps for page separation and correspondinggap images. The gap images can be used as references in a subsequentimage processing procedure so that the continuous image can be dividedinto separate pages of images, each corresponding to an individualsheet.

Further scope of the applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention.

FIG. 1 is a schematic illustration showing a scan apparatus according toa first embodiment of the invention.

FIG. 2 is a schematic illustration showing a scan apparatus according toa second embodiment of the invention.

FIG. 3 is a schematic illustration showing an image processing procedureaccording to the second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings,wherein the same references relate to the same elements.

FIG. 1 is a schematic illustration showing a scan apparatus according toa first embodiment of the invention. Referring to FIG. 1, an automaticsheet feeder 1 with assemblies for transporting a sheet S at differentspeeds according to this embodiment of the invention includes a base 10and a sheet transporting mechanism 20.

The base 10 may be composed of a single member or a plurality of membersand has a sheet passageway 11, which may be formed by a plurality ofguide plates. The sheet passageway 11 can be U-shaped or L-shaped.

The sheet transporting mechanism 20 disposed on the base 10 transportsthe sheet S through the sheet passageway 11. In this embodiment, thesheet transporting mechanism 20 includes a first transporting assembly22 and a second transporting assembly 24, which is disposed downstreamof the first transporting assembly 22. The downstream side is determinedbased on a moving direction of the sheet S. That is, the sheet S is atfirst transported by the first transporting assembly 22 and then by thesecond transporting assembly 24.

The automatic sheet feeder 1 has an opening 12, which is formed in thesheet passageway 11 and between the first transporting assembly 22 andthe second transporting assembly 24, and the opening 12 exposes aportion of the sheet S. The first transporting assembly 22 transportsthe sheet S to the opening 12 at a first speed V1, and the secondtransporting assembly 24 transports the sheet S away from the opening 12at a second speed V2 higher than the first speed V1. When multiplesheets are transported sequentially, the difference between the secondspeed V2 and the first speed V1 will generate gaps between successivesheets.

In addition, the automatic sheet feeder 1 may further include a feedingtray 30. The feeding tray 30, disposed on the base 10 and connected tothe sheet passageway 11, supports the sheet S or a stack of sheetsincluding the sheet S. The first transporting assembly 22 transports thesheet S into the sheet passageway 11 from the feeding tray 30. It is tobe noted that the feeding tray 30 may be omitted under theconsiderations of the cost and the space. In this case, the user cansupport the stack of sheets by his/her hand so that the sheets can befed.

In this embodiment, the first transporting assembly 22 includes a firstroller 221 and a frictional element (e.g., a friction pad) 222 locatedopposite the first roller 221, and the first roller 221 and thefrictional element 222 separate the sheet S from the stack of sheets andtransport the sheet S into the sheet passageway 11 and to the opening12, wherein the first roller 221 is disposed in the sheet passageway 11.The first roller 221 may cooperate with another idle roller (not shown)to transport the sheet S.

Similarly, the second transporting assembly 24 includes a second roller241 disposed in the sheet passageway 11, and the second roller 241transports the sheet S away from the opening 12 and out of the sheetpassageway 11. The second transporting assembly 24 can include an idleroller 242, and the second roller 241 and the idle roller 242 cooperatewith each other to transport the sheet S. The first roller 221 and thesecond roller 241 may be driven by the same power source (e.g., a motor)13 or different power sources.

In order to obtain the difference between the second speed V2 and thefirst speed V1, the first roller 221 and the second roller 241 arerotated at different angular velocities in the case that outer diametersof the first roller 221 and the second roller 241 are equal.Alternatively, the first roller 221 and the second roller 241 arerotated at the same angular velocity, in the case that outer diametersof the first roller 221 and the second roller 241 are unequal.

In order to make the sheet S be transported through the sheet passageway11 smoothly, the automatic sheet feeder 1 can further include a guidingelement 14, disposed downstream of the first transporting assembly 22,for guiding the sheet S to the second transporting assembly 24.

In this embodiment, the automatic sheet feeder 1 is used in conjunctionwith a flatbed scanner 6 including a housing 62, a scan platen 64 and ascan module 66.

The scan platen 64 is mounted on the housing 62. The scan module 66disposed in the housing 62 may move back and forth along a guiding rod68 or may move to a predetermined position to continuously scan throughthe scan platen 64 and the opening 12 the sheet S and thus generate acorresponding image. The scan module 66 may comprise a charge-coupleddevice (CCD) sensor or a contact image sensor (CIS). In this embodiment,a CCD image sensor 664 is utilized in the scan module 66, which furtherincludes a light source 661, a reflecting mirror 662 and a lens 663.

FIG. 2 is a schematic illustration showing a scan apparatus according toa second embodiment of the invention. FIG. 3 is a schematic illustrationshowing an image processing procedure according to the second embodimentof the invention. As shown in FIGS. 2 and 3, this embodiment is similarto the first embodiment except that this embodiment focuses upon theimage processing.

The scan apparatus with assemblies for transporting a sheet at differentspeeds according to this embodiment of the invention includes anautomatic sheet feeder 1 and a flatbed scanner 6. The automatic sheetfeeder 1 is disposed on the flatbed scanner 6. The automatic sheetfeeder 1 and the flatbed scanner 6 are similar to those of the firstembodiment, so detailed descriptions thereof will be omitted. The sheettransporting mechanism 20 disposed on the base 10 sequentiallytransports a first sheet S1 and a second sheet S2 through the sheetpassageway 11. The automatic sheet feeder 1 comprises animage-processing area 12 which can be an opening or a transparentwindow, for example. The first transporting assembly 22 transports thefirst sheet S1 and the second sheet S2 sequentially to theimage-processing area 12 at the first speed V1. The second transportingassembly 24 transports the first sheet S1 and the second sheet S2sequentially away from the image-processing area 12 at the second speedV2.

In the flatbed scanner 6, the scan module 66 continuously scans thefirst sheet S1 and the second sheet S2 within the image-processing area12, and generates a continuous image 90. The image-processing area 12exposes a portion of the first sheet S1 and a portion of the secondsheet S2, so through the image-processing area 12 the scan module 66 canscan the first sheet S1 and the second sheet S2. The continuous image 90includes a first sheet image 91 corresponding to the first sheet S1, asecond sheet image 92 corresponding to the second sheet S2 and a gapimage 93 corresponding to a gap between the first sheet S1 and thesecond sheet S2.

The first roller 221 of the first transporting assembly 22 is disposedin the sheet passageway 11. The first roller 221 and the frictionalelement 222 separate the first sheet S1 from the second sheet S2 andsequentially transport the first sheet S1 and the second sheet S2 intothe sheet passageway 11 and to the image-processing area 12.

The second roller 241 of the second transporting assembly 24, which isdisposed in the sheet passageway 11, transports the first sheet S1 andthe second sheet S2 sequentially away from the image-processing area 12and out of the sheet passageway 11. The guiding element 14 guides thefirst sheet S1 and the second sheet S2 sequentially to the secondtransporting assembly 24.

In order to perform page separation that divides a continuous image intoseparate pages of images, the scan apparatus can further include animage-processing device 80, which is electrically connected to the scanmodule 66. The image-processing device 80 receives and processes thecontinuous image 90 according to the gap image 93 corresponding to thegap and thus divides the continuous image 90 into separate pages ofimages, that is, the first sheet image 91 and the second sheet image 92.The image-processing device 80 may be disposed in the flatbed scanner 6or disposed in the automatic sheet feeder 1. The electrical connectionincludes, without limitation to, a wired or wireless connection.

In another way, an external image-processing device, for example, apersonal computer, can be electrically connected to the scan apparatusand the scan apparatus outputs the continuous image 90 to the externalimage-processing device. In this case, the external image-processingdevice processes the continuous image 90 and divides the continuousimage 90 into the first sheet image 91 and the second sheet image 92according to the gap image 93.

According to the embodiments of the invention, multiple sheets can besuccessively scanned without using a sheet detector, and the gaps forpage separation can be simultaneously generated. However, this does notimply that the sheet detector cannot be used. The gaps for pageseparation can be used in the subsequent image processing procedure sothat the continuous image can be divided into separate pages of images.The function of current image-processing devices (e.g., a computer or amicroprocessor) is getting more and more powerful, so that the scanapparatus with an image-processing device and the automatic sheet feederof the invention can generate discrete images of the sheets like aconventional scan apparatus having sheet detectors. Therefore, thecontrol circuit and the hardware elements of the scan apparatus can beeffectively simplified, and the cost of the scan apparatus can be thusreduced.

While the invention has been described by way of examples and in termsof preferred embodiments, it is to be understood that the invention isnot limited thereto. To the contrary, it is intended to cover variousmodifications. Therefore, the scope of the appended claims should beaccorded the broadest interpretation so as to encompass all suchmodifications.

1. An automatic sheet feeder, comprising: a sheet passageway; an openingformed in the sheet passageway; and a sheet transporting mechanism fortransporting a sheet through the sheet passageway, the sheettransporting mechanism comprising: a first transporting assembly; and asecond transporting assembly disposed downstream of the firsttransporting assembly, wherein: the first transporting assemblytransports the sheet to the opening at a first speed; and the secondtransporting assembly transports the sheet away from the opening at asecond speed higher than the first speed.
 2. The automatic sheet feederaccording to claim 1, further comprising a feeding tray for supportingthe sheet, wherein the first transporting assembly transports the sheetfrom the feeding tray into the sheet passageway.
 3. The automatic sheetfeeder according to claim 2, wherein: the first transporting assemblycomprises a first roller and a frictional element located opposite thefirst roller for separating the sheet from a stack of sheets andtransporting the sheet into the sheet passageway.
 4. The automatic sheetfeeder according to claim 1, wherein the first transporting assemblycomprises a first roller, disposed in the sheet passageway, fortransporting the sheet to the opening.
 5. The automatic sheet feederaccording to claim 4, wherein the second transporting assembly comprisesa second roller, disposed in the sheet passageway, for transporting thesheet away from the opening and out of the sheet passageway.
 6. Theautomatic sheet feeder according to claim 5, further comprising a powersource, wherein the first roller and the second roller are driven by thepower source.
 7. The automatic sheet feeder according to claim 5,wherein outer diameters of the first roller and the second roller areequal.
 8. The automatic sheet feeder according to claim 5, wherein outerdiameters of the first roller and the second roller are unequal.
 9. Theautomatic sheet feeder according to claim 1, further comprising: aguiding element, disposed downstream of the first transporting assembly,for guiding the sheet to the second transporting assembly.
 10. A scanapparatus, comprising: an automatic sheet feeder comprising: a sheetpassageway; an image-processing area; and a sheet transporting mechanismfor sequentially transporting a first sheet and a second sheet throughthe sheet passageway, the sheet transporting mechanism comprising: afirst transporting assembly; and a second transporting assembly disposeddownstream of the first transporting assembly, wherein: the firsttransporting assembly transports the first sheet and the second sheet tothe image-processing area at a first speed, and the second transportingassembly transports the first sheet and the second sheet away from theimage-processing area at a second speed higher than the first speed; anda scan module for continuously scanning the first sheet and the secondsheet within the image-processing area and generating a continuousimage, which comprises a first sheet image corresponding to the firstsheet, a second sheet image corresponding to the second sheet and a gapimage corresponding to a gap between the first sheet and the secondsheet.
 11. The scan apparatus according to claim 10, further comprisinga feeding tray for supporting the first sheet and the second sheet, andthe first transporting assembly sequentially feeds the first sheet andthe second sheet from the feeding tray into the sheet passageway. 12.The scan apparatus according to claim 11, wherein the first transportingassembly comprises a first roller and a frictional element locatedopposite the first roller for separating the first sheet from the secondsheet and sequentially transporting the first sheet and the second sheetinto the sheet passageway.
 13. The scan apparatus according to claim 10,wherein the first transporting assembly comprises a first roller,disposed in the sheet passageway, for transporting the first sheet andthe second sheet sequentially to the image-processing area.
 14. The scanapparatus according to claim 13, wherein the second transportingassembly comprises a second roller, disposed in the sheet passageway,for transporting the first sheet and the second sheet sequentially awayfrom the image-processing area and out of the sheet passageway.
 15. Thescan apparatus according to claim 14, further comprising a power source,wherein the first roller and the second roller are driven by the powersource.
 16. The scan apparatus according to claim 14, wherein outerdiameters of the first roller and the second roller are equal.
 17. Thescan apparatus according to claim 14, wherein outer diameters of thefirst roller and the second roller are unequal.
 18. The scan apparatusaccording to claim 10, further comprising: a guiding element, disposeddownstream of the first transporting assembly, for guiding the firstsheet and the second sheet sequentially to the second transportingassembly.
 19. The scan apparatus according to claim 10, furthercomprising: an image-processing device, electrically connected to thescan module, for receiving and processing the continuous image, whereinthe image-processing device divides the continuous image into the firstsheet image and the second sheet image according to the gap image. 20.The scan apparatus according to claim 10, wherein the scan apparatusoutputs the continuous image to an external image-processing deviceelectrically connected to the scan apparatus, wherein the externalimage-processing device processes the continuous image and divides thecontinuous image into the first sheet image and the second sheet imageaccording to the gap image.